Respuesta :

Answer:

x = 17

Step-by-step explanation:

5x - 18 and 4x + 45 are adjacent angles on as straight line and sum to 180° , so

5x - 18 + 4x + 45 = 180 , that is

9x + 27 = 180 ( subtract 27 from both sides )

9x = 153 ( divide both sides by 9 )

x = 17